Glow Worm Micron 50FF

My heating and hot water keeps going off. Inside the boiler there are 2 green lights. 1 says 'reset' the other says 'burner on'. When the heating / hot water goes off, these lights are both flashing.

Someone has had a look and says it may need an 'electrical thermisor' (part no. 227057).

Gary, January 2006

What causes ignition lockout

John, February 2015

non volatile lockout fault coding says do i need to replace pcb

patricia colton, July 2014

I've had a Glow Worm Micron Boiler for about 15 years now, It has been very reliable despite what many others say. I did fail a few years back, but that wasn't even the boilers fault, it was water that leaked on the control pcb. This is the original pcb still in mine, one with lots of transistors, diodes and resistors that you can repair it if does go wrong, I replaced the faulty components and it was starting up but kept cutting out, which was a faulty Relay, I replaced the relay and there was one genuine fault which was repaired, can't remember now what I replaced, but it cost about £20 and since then it's been perfect, untill the fan being worn out after 15 years of use, so I have just replaced the bearings, which isn't easy as you struggle to get it apart, but it's back working again.

bods, January 2014

Have had the usual problems,pcb with dry joints ,but got my board from eBay for £20 new and has worked for 11 yrs ,) the fan has started to make a little noise and I've looked at the price and they range from £49 to £149 ,( not sure wether to change or get another boiler ,()

Trevor the sparky from bishopstoke, February 2013

My boiler burner won't switch on it just goes to reset after the light up sequence this is a glow worm micron 50off
Can anyone help - the burner does light after several attempts at at reset anticlockwise

Steve s, July 2012

replaced thermistor quite easy..it just slides out of the threaded nut...by the way the thermister only lasted month so i gotta get a new one...i'm hoping it was a faulty one cause syptems are the same...

banzai29, February 2011

Turned the gas off to replace a broken gas hob.Fitted new one, now the boiler won't work. Where do i start fault finding?

The hubbards, January 2011

same problem as many of you, the fan bearings siezed up twice now , first time had a replacement fan 2nd time regreased it , its now squeeling again , i notice roger on this page says he replaced the bearing and wondered if he or anyone could tell me where to purchase them

cold glenn, June 2010

I bought a Glow worm Micron 50FF. After 8 months the pcb burnt out, this was changed under warrantee, approx 6 months later the pcb burnt out again, I asked around and it turned out that this was a known fault, I spoke politely to the Glow Worm Warrantee Dept. they were not interested and just denied that there was a fault. I have had to buy FIVE more pcbs, one a year (always in the winter of course!) The very last pcb has lasted three years. It looks quite different with silicone chips instesd of old fashioned diodes etc. I have also replaced three thermisters and the fan bearings have siezed. I replaced the fan bearings they were £3.00 each because I did not want Glowworm to have any more of my money! The boiler has just failed again now, at least it's the summer. I am very bitter now about Glow Worms attitude, I could have bought a cheap boiler but stupidly thought a "quality" one would last longer and be trouble free ha ha! All you can do is tell everyone who will listen what a load of JUNK Glow Worm is and hope that they go bankrupt! Also, only use non-genuine parts so they don't get any more of your money! (They can't be any worse quality than genuine Glow Worm parts can they?)

Roger, May 2010

Had what i thought was a pressure switch failure only to find the switch was OK - it was not operating due to a blocked air venturi (which is inside the fan assembly). The venturi supplies the air pressure switch with low and higher pressure air via 2 pipes - this differential of around 1 millibar causes the switch to operate. The cause of the blockage was a build up of spiders web which blocked the venturi tube enough to stop it working correctly. To clean the venturi you remove the fan assembly then one screw to remove the venturi pipe. A simple and cost free fix!!!

Baz D - maintenance electrical engineer, May 2010

I have the same problem with lights flashing, gas ignition failure and cold water pumping through the radiators.

I suspect the solution is to get rid and start again, it will be cheaper in the long run!

AMP, March 2010

My boiler has done the same thing and the manual says it is a 'blocking error'. i have no idea what this means. Meanwhile switching off and restarting solved the problem - for now!

Jenny, February 2010

I have had numerous PCB changes in the short life of my 50FF, each time it fixed the problem for a short while. I have had the thermistors replaced, which fixed the problem once. the latest problem, just before christmas involved no lights on the boiler and it was the Fan sticking, the engineer said this is quite common, and they normally grease them which only lasts a short while. He replaced mine, but when I came home tonight, the dreaded lights were flashing again, a reset cured it this time though, I don't know how long it will last this time before I get the engineer out again.

Mike G, January 2010

chech your user guide it tells you what has gon by the way the lights flash

dean the gas man, December 2009

I have a micron 30-80cff i have 240v to fan, gas valve
pump etc but when it trys to fire there is no spark or voltage to the spark electrode

Deano, October 2009

replace pcb part no.2000801990 £131.23 ex vat from heatingsparepart.com

mi doyle, February 2009

when changing pcb always change thermistor as a matter of course on these boilers

30yr exp ex bg, January 2009

I am also having a similar problem atm!

For the past few months, the boiler used to cut out and the reset light would start to flash... After turning the unit off for a few min and then back on again, it would work fine....

But thismorning, there seems to be no life in the boiler, no lights or anything.... Ive turned the unit off, and back on again, you can hear the fan start up, but no ignition process at all!

Called British Gas (on their insurance sceme) and no one can come out till tomorow :O (advert said if you call before 9, someone would be there to see you on the same day)

Now its below freezing outside atm, and its been like this for the past few days, its freezzing in the house and i cant get a shower or anything untill its fixed :O

Not impressed!

James Simpson, February 2008

my boiler is doing the same and its the fan for the flue thats the fault, it was noisy then it switched itself off, my corgie friend had a look at if freed the fan and its now working but to be on the safe side its haveing a new fan fitted as it will break down on christmas eve.

tony, November 2007

MY GLOW WORM MICRON 50FF COMES ON INTERMITENTLY I USE IT ON MANUAL BUT BOTH THE PILOT AND BURNER LIGHTS ARE NOT WORKING

RICHARD BECKETT, November 2007

Can someone please tell me generally how to replace this thermister. I have a replacement, see that it goes in the top of the boiler chamber, but goes into a threaded plug type fitting. Does this have to be removed/loosened to put the new one in or does it simply slide out (Up) and the new one get slid back down in?

Thanks

Jim

Jim, October 2007

Can someone please tell me generally how to replace this thermister. I have a replacement, see that it goes in the top of the boiler chamber, but goes into a threaded plug type fitting. Does this have to be removed/loosened to put the new one in or does it simply slide out (Up) and the new one get slid back down in?

Thanks

Jim

Jim, October 2007

I have got the same problem. I have changed the PCB but this hasn't fixed it (I changed it for the new PCB design). I am now going to try the thermistor.

Good Luck!

Guy, January 2007

Always go through the process of elimination. Cheapest part first. This is a common fault and i would advise trying the thermisters before buying a £130 Circuit board.

Jamie - Heatforce engineer, November 2006

THE P.C.B'S HAVE BEEN UPDATED SEVERAL TIMES SO IF THE THERMISTOR DOES NOT WORK, IT WILL BE THE P.C.B

CURRENT B.G ENGINEER

MIKE, October 2006

I have the very same problem with my Micron 60.
I have changed the pcb,pressure switch,gas valve and safety temp limiter. Still same problem.
I will try the thermistor,fingers crossed.

russell, August 2006

Hi, We had the same problem and changing the thermistor seems to have worked. For approximately £15 its worth trying. Good luck.
Paul and Sarah.

Paul and Sarah, January 2006

more than likely p.c.b mate ex british gas

dee, January 2006